報告書番号

482011

タイトル（和文）

地中熱交換温室の熱的性質に関する非定常シミュレーションモデルの開発

タイトル（英文）

DEVELOPMENT OF THE NON-STEADY STATE SIMULATION MODEL FOR GREENHOUSE WITH UNDERGROUND HEAT EXCHANGE SYSTEM

概要 （図表や脚注は「報告書全文」に掲載しております）

省エネルギー温室として広く普及している地中熱交換温室の性能を気象条件および土壌の熱特性から評価するモデルの開発を行った。モデルによる解析結果は，実際の地中熱交換温室の特性を良く表現しており，このモデルによって地中熱交換温室の性能予測が可能であることを検証した。

概要 （英文）

UNDERGROUND HEAT EXCHANGE SYSTEM FOR GREENHOUSE DEVELOPED BY YAMAMOTO IS SO SIMPLE AND RELATIVELY HIGH EFFICIENT THAT IT HAS BEEN SPREADING INTO THE HORTICULTURAL PRODUCTION IN RECENT YEARS. MATHEMATICAL MODEL OF THIS SYSTEM WAS DERIVED FOR PERFORMANCE PREDICTION USING METEOROLOGICAL CONDITIONS AND THERMAL CONDITIONS OF SOIL.IN THIS MODEL,TO SIMULATE THE REAL THERMAL PHENOMENA IN THIS SYSTEM CLOSELY,THERMAL CONDITIONS OF THE UNDERGROUND PART WERE EXPRESSED AS NON-STEADY SATE AND TWO DIMENSIONAL DIFFERENCE EQUATION WAS APPLIED FOR CALCULATING.THE OTHER PARTS WERE EXPRESSED STEADY STATE. WHEN INPUT CONDITIONS WERE AMBIENT AIR TEMPERATURE AND INSOLATION CONVERTED INTO FOURIER SERIES,FURTHER,MOISTURE CONDITIONS OF SOILD AND INITIAL SOIL TEMPERATUREWERE APPROPRIATELY SET UP,THIS MODEL COULD EXPRESS WELL THE TEMPERATURE REGIME INSIDE THE GREENHOUSE,AMOUNT OF THE SOLAR ENERGY COLLECTION AND AMOUNT OF THE NIGHTTIME HEATING USE OF THE ACTUAL UNDERGROUND HEAT EXCHANGE SYSTEM. SINCE ACCURACY OF THIS MODEL WAS RECOGNIZED ENOUGH,THE PERFORMANCE OF THE DOUBLE COVERED GREENHOUSE(6MX20M) WITH UNDERGROUND HEAT EXCHANGE SYSTEM WAS EXAMINED BY THIS MODEL WHOSE CONSTANTS WERE CHANGED. BY VARYING THE NUMBER OF HEAT EXCHANGE PIPES BURIED IN FROM 6 TO 30,THE EFFICIENCY OF THE SOLAR ENERGY COLLECTION OF THIS SYSTEM VARIED FROM 6 TO 20%. THE OPTIMUM PIPE LENGTH WAS FOUND TO BE 20M WHEN SOIL TEMPERATURES SURROUNDING THE PIPES WERE UNIFORM.AS TEMPERATURE GRADIENTS WERE MADE ALONG THE PIPES BY PASSAGE OF THE AIR INTO THE PIPES,THE OPTIMUM PIPE LENGTH WAS NOT FOUND.

報告者

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